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apparently reflects natural conditions. <br />Overburden 4ell 140V exceeded the pH limit of 6.50 to 8.50 with a value of 6.10 in June, <br />1993. The EPA, however, has set irrigation pH limits of 4.50 to 9.00 (EPA, 1976). <br />AC the Seneca II-W shop well (Well 201TC ), CDOH drinking water standards were used to <br />determine its suitability. The secondary standard for iron (0.3 mg/l) was exceeded with <br />values of 10.30 (November, 1992) and 4.73 mg/L (June, 1993). The secondary standard for <br />manganese (0.05 mg/l) was exceeded with values of 0.23 (November, 1992) and 0.15 mg/l <br />(June, 1993). the human health standard for mercury (2 ug/l) was exceeded once (November, <br />1992) with a value of 10 ug/l. Since this mercury value is also the detection limit, it <br />should be reviewed with caution. However, bottled water is consumed at Seneca II-W. <br />Also, since the aquifer for the shop well (Trout Creek Sandstone) starts at 280 feet below <br />the Wadge Coal and is separated by confining shale layers, water from this well should not <br />be affected by mining end, therefore, reflects the natural charaeteristics of the aquifer. <br />Tab 7 of the Seneca II-W PAP contains a section that discusses the suitability of using <br />• <br />water from the various aquifers monitored at the Seneca 11-W Mine for irrigation or <br />livestock watering. The discussion mentions that all aquifers at the Seneca 11-W Mine • <br />have exhibited several parameter concentrations in excess of both irrigation and livestock <br />standards compared, rendering them questionable regarding their suitability for either <br />irrigation or livestock. All bedrock aquifers affected by mining have been determined to <br />have transmissivities less than 1 ft2/day, which Would also preclude their use for <br />yielding sufficient water for irrigation, or even livestock. <br />Ground Water Duality Summary. The limited amount of mining that has occurred at this mine <br />(mining began in 1990) has had no effect on ground water quality during the 1993 water <br />year. TDS increases above baseline ranges can be attributed to natural conditions (Well <br />15W. Average TDS values in 1993 Were less than the baseline range for Wells 140V, 170V, <br />180V, 17W and 18W. <br />Surface 4ater <br />At Seneca II-W, atl stream sites are monitored monthly (excluding December to March) for <br />flow and field parameters. Samples obtained at these sites are analyted for the surface <br />_, • <br />8 <br />